This invention relates to an impact bar securable to the rotor of an impact crusher or similar comminuting machine. The impact bar has a length measured in a direction generally radially to the rotor. The shape of the cross section of the bar taken along a plane parallel to the plane of rotation of the rotor is bent symmetrically in the length dimension of the bar in an approximately C-shape whose opening is at the front or leading side of the impact bar as viewed in the direction of rotation. The impact bar has a constriction in its symmetry plane, and the reverse side (trailing side) of the bar is adapted to be supported against tangential forces radially outwardly of the constriction.
An impact bar of the above-outlined type is known and is disclosed, for example, in German Pat. No. 930,839. The impact bar described therein has a cross-sectionally C-shaped or V-shaped configuration by virtue of the fact that it has, on its leading side as viewed in the direction of rotation of the rotor on which it is installed, a longitudinally extending recess or notch of obtuse angle. The impact bar is tightened to the rotor by special clamping pieces projecting into the recess and engaging the deepest location of the recess which, at the same time, constitutes the constriction for the impact bar. The rotor is designed such that during work the impact bar is with its planar reverse side - as related to the rotor axis - backed up externally of the constriction while tangential forces are effective. Because of the thinness of the known bar in its mid portion, that is, in the zone of its symmetry plane, risks of breakage are very high. If, in order to lessen such risks, the constriction is formed by a flatter configuration of the recess and thus the thickness of the impact bar is increased at the constriction, a firm holding of the impact bar against the high centrifugal forces acting in a radially outward direction is no longer sufficiently ensured.